Material forming apparatus

ABSTRACT

An apparatus (10) for forming paste-like materials into discrete product units, comprising an elongate, open ended tube (11) of substantially constant internal cross-sectional shape, an inlet port (37) through the wall of the tube intermediate its ends to allow the entry of the paste-like material into the interior of the tube, first and second piston members (12, 13) spaced apart in axial alignment and adapted to be moved together relative to the tube between a position in which the space between them is effectively external of the tube and a position in which that space is completely within the tube and in communication with the inlet port therein.

FIELD OF THE INVENTION

The present invention relates to apparatus for forming paste-likematerials into discrete product units and more particularly to apparatusof the type which can form such discrete product units from paste-likematerials containing fibrous ingredients.

BACKGROUND OF THE INVENTION

It is well known to form elongate articles of uniform cross-section bycontinuously extruding a run of the material in a suitablecross-sectional form and periodically severing the extrusion to producea plurality of the articles of the required length. It has been foundthat this regular severing does not work satisfactorily when theextrusion is of a material containing fibres as in the case of thefibrous meat products the subject of co-pending Australian patentapplication (No. PG4670) entitled "Meat Product and Process".

SUMMARY OF THE INVENTION

The present invention provides an alternative apparatus for formingpaste-like materials, including the meat product described above, intodiscrete product units.

The present invention consists of apparatus for forming paste-likematerials into discrete product units comprising an elongate, open endedtube of substantially constant internal cross-sectional shape, an inletport through the wall of the tube intermediate its ends to allow theentry of paste-like material into the interior of the tube, a pistonmeans including first and second piston members spaced apart in axialalignment and adapted to be moved together relative to the tube betweena first position in which the space between them is effectively externalof the tube and a second position in which that space is completelywithin the tube and in communication with the inlet port therein.

In another aspect, the present invention consists of a method for theformation of discrete product units of a paste-like material, comprisingintroducing the paste-like material under pressure through an inlet portinto a space defined within a tube of substantially constant internalcross-sectional shape and bounded at either end by a pair of spacedapart piston members, moving the pistons together relative to the tubesuch that the space between the pistons is effectively external of thetube, and removing the product unit from between the piston members.

The tube is preferably a tube of stainless steel or like material whichmay be of any desired internal cross-sectional shape. The tube hasintermediate its ends an inlet port for the material to be formed intodiscrete product units and a bleed hole for air. The material issupplied through a suitable line from a pressurized source to the inletport.

The piston means preferably comprises a pair of elongate pistons whichare a close sliding fit within the bore of the tube. These pistons arepreferably joined together externally of the tube in a manner such thatthe distance between the opposed faces of the axially aligned pistonsmay be varied to enable the length of the discrete product units to becorrespondingly varied. It will be appreciated that the cross-sectionalshape of the formed unit will be determined by the cross-sectional shapeof the internal bore of the tube.

The piston members will be reciprocally mounted in a manner such thatthey may be moved between a first position in which one of the pistonsis completely external of the tube and the active face of the otherpiston is at or projecting from an effective end of the tube and asecond position in which the opposed, active, faces of the pistons areboth within the tube and the space therebetween is in communication withthe material inlet port and with the air bleed hole. In the secondposition the material will enter the space between the pistonsdisplacing air through the bleed hole as it does so. As the pistons aretogether moved towards the first position the material between thepistons will be moved relatively along the tube. As this happens one ofthe pistons will pass across the entry port which simultaneously effectsa closure of the port and a severing of the material which is within thespace between the pistons from the supply of that material. If thematerial contains fibrous ingredients the piston can effect a cleanseparation of the discrete material unit being formed from the bulksupply of the material. The further travel of the unit of material alongthe tube between the pistons will also serve to confirm the clean linesof the unit so formed. When the pistons reach the first position thearticle will fall from between the pistons under the influence ofgravity or may be removed therefrom by a gas blast, by mechanical meansor in any other desired manner. As the pistons return to the secondposition the inlet port will be uncovered, material will flow into thespace between the pistons within the tube and the cycle will berepeated.

If desired a lubricant may be applied to the end of the pistonprojecting from the tube to assist in freeing the formed article fromthat piston. This lubricant could be water, batter, an edible oil or thelike depending upon the nature of the material being formed intodiscrete units.

The pistons are preferably not merely moved between the first and secondpositions but are preferably caused to undergo a short oscillation ateach of those extreme positions in order to, in the second position,form the ends of the article clearly within the space between thepistons, and, in the first position, to clearly separate the articlefrom the pistons.

The apparatus and method according to this invention allow a fibrouspasty material, particularly a meat paste containing many fibrousparticles, to be formed into a discrete product unit with clean edgesand no individual fibres discernable as projecting from the article.

The pistons may be caused to reciprocate within the tube in any knownmanner; however, it is preferred that the pistons are both linked,through a link arm, to an arm which is caused to rotate through an arcwhich is slightly greater than 180°. Such an arrangement can be used toproduce a short oscillation of the pistons at at least at one end oftheir travel.

It will be appreciated that the tube may not physically terminate at thepoint at which the material units are removed from between the pistons.If desired the tube may merely include an aperture or space throughwhich the formed material unit may be removed from between the pistons.It is to be understood that such an arrangement falls within the scopeof the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter given by way of example only is a preferred embodiment ofthe present invention described with reference to the accompanyingdrawings in which:

FIG. 1 is a diagrammatic cross-sectional view of an apparatus accordingto the present invention with the pistons in a position in which aformed material unit may be released, and

FIG. 2 is a detailed diagrammatic cross-sectional view of the tube andpistons of the apparatus of FIG. 1 in a position in which the spacebetween the pistons is being filled with material.

DETAILED DESCRIPTION OF THE DRAWINGS

The apparatus 10 is particularly designed for forming a paste-likedispersion of meat including fibrous strands of meat into discrete meatunits such as meat "fingers" or meat "chips". In order to haveappropriate consumer appeal and in order to reduce the possibility ofbacterial spoilage it is desirable that the "fingers" or "chips" formedfrom the meat paste have no fibrous projections extending therefrom. A"whiskery" appearance is unacceptable in the market place. The presentapparatus 10 accepts a pressurised supply of the meat paste and convertsit into "fingers" of constant cross-sectional shape and of apredetermined length.

The apparatus 10 comprises essentially a tube 11 having a square sectionbore and, a pair of pistons 12 and 13 adapted to reciprocate relative tothe tube 11 and a drive means 14 to bring about that reciprocation.

The drive means 14 includes an electric motor 15 which carries at oneend a V-pulley 16. The electric motor 15 drives a reduction V-pulley 17through vee belt 18. The V-pulley 16 is mounted on a shaft 19 which alsocarries a drive gear 21. The drive gear in turn drives a crank gear 22which is considerably larger than the drive gear 22 to provide a furtherreduction in the rotational speed. The crank gear 22 is mounted on afurther shaft 23 lying parallel with shaft 19.

The crank gear 22 carries a crank pin 24 extending laterally from thecrank gear 22 parallel to the shaft 23 and located radially between theshaft 23 and circumferential teeth on the crank gear 22. A rack arm 25is journalled onto the crank pin 24 at one of its ends and extendssubstantially tangentially from the crank gear 22. The end of the rackarm 25 distal to the crank pin 24 carries on its upper surface an arrayof rack teeth 26. The rack arm 25 is supported beneath the rack teeth 26by a support pad 27 which is pivotaly mounted on pin 28 extendingtransversely of the axis of the rack arm 25.

A pinion 29 is mounted on a shaft 31 and has teeth which mesh with therack teeth 26. An arc lever 32 extends radially of the shaft 31 to whichit is adjustably connected by locking screw 33. The arc lever 32 isconnected through a bearing 34 to crank arm 35. The crank arm 35 is inturn connected to the pistons 12 and 13 as will be hereinafterdescribed.

In operation the drive means 14 causes the pistons 12 and 13 toreciprocate. The rotary motion of the electric motor is transmitted tocrank gear 22 through pulley 16, vee belt 18, pulley 17, shaft 19 andgear wheel 21. The rotary motion of the crank gear 22 is converted intoa reciprocating motion of the rack teeth 26. The reciprocation of therack teeth causes an arcuate oscillation of the pinions 29 and the arclever 32 which in turn causes a complex linear reciprocation of thecrank arm 35. As the crank gear 22 rotates the crank pin 24 moves in acircular path and the rck teeth 26 move along an essentially linearpath. The relationship between the crank wheel 22, crank pin 24, rack 25and pinion 29 is such that the pinion will oscillate through an arc of250°, which arc takes the arc arm 34 above a notional horizontal linethrough the axis of shaft 31. This means that the free end of the crankarm 35 will, in one counterclockwise cycle of the arc lever 32, moveaway from the pinion 29, as the arc lever 32 moves down to the saidnotional horizontal line, then moves towards the pinion 29, as the arclever 32 is moved through 180° and again meets the notional horizontalline, and finally moves away from the pinion 29, as the arc lever 32rises above the notional horizontal line. As the pinion 29 is moved backin a clockwise direction the reciprocation of the free end of the crankarm 35 will be opposite to that described.

The tube 11 is of square section and has a square section bore. Thepistons 12 and 13 are of square cross-sections and are a close slidingfit in the bore of the tube 11. The tube 11 is mounted in a stationarymanner on a frame (not shown) of the apparatus. A duct 36 carrying meatpaste from a pressurised container (not shown) is operatively connectedto the bore of the tube 11 through an inlet port 37 in the tube 11. Anarrow diameter air bleed hole 38 is provided in the tube adjacent theinlet port 37.

The piston 12 comprises one arm of a C-shaped member, the piston 12being connected to a vertical member 39 which is in turn connected to ahorizontal member 41 lying parallel to piston 12 above the tube 11. Thehorizontal member 41 is considerably longer than tube 11 and issupported thereon by nylon bush 42. At its end distal to member 39 thehorizontal member 41 is connected to a further vertical member 43 formedat its free end with an aperture 44 into which the piston 13 fits and isheld in axial alignment with piston 12 by locking screw 45. The distancebetween pistons 12 and 13 may be varied by loosening screw 45 and movingthe piston 13 through aperture 44. This variation of the distancebetween the pistons 12 and 13 will, of course, vary the length of theformed material unit.

The horizontal member 41 is formed with a vertically upwardly extendinglug 46 which is connected through a roller bearing to the crank arm 35of the drive means 14. The pistons 12 and 13 are thereby caused toreciprocate in the manner previously described relative to the tube 11.

In operation as the pistons 12 and 13 are drawn back (to the right asseen in FIGS. 1 and 2) through the tube 11 the inlet port 37 will beuncovered and the meat paste will flow into the bore of the tube 11while displacing air through bleed hole 38. The meat paste will becontained within the tube 11 between the pistons 12 and 13. As thepistons 12 and 13 are then moved out of the tube (to the left as seen inFIGS. 1 and 2) the unit of meat paste within the tube 11 will be severedfrom the paste supply at the inlet port 37. When the active faces of thepistons 12 and 13 are both clear of the tube 11 the unit of formedmaterial 47 will be free to fall clear of the pistons 12 and 13 as seenin FIG. 1. A tube 48 is provided to spray a release agent such as wateror batter onto the free end of piston 12 as each unit 47 is ejected fromthe tube 11.

What is claimed is:
 1. An apparatus for forming paste-like materialsinto discrete product units comprising an elongate, open ended tube ofsubstantially constant internal cross-sectional shape, an inlet portthrough the wall of the tube intermediate its ends to allow the entry ofpaste-like material into the interior of the tube, a piston meansincluding first and second piston members spaced apart in axialalignment and adapted to be moved together relative to the tube betweena first position in which the space between them is effectively externalof the tubes and a second position in which that space is completelywithin the tube and in communication with the inlet port therein, theapparatus further including means adapted to cause the piston members toundergo a short oscillation when at the first and/or second positions.2. An apparatus as claimed in claim 1 in which the means adapted tocause the piston members to undergo a short oscillation when the firstand/or second positions comprises a crank arm pivotably connected to thepiston means and pivotably connected to an arc lever, the arc leverbeing connected to drive means adapted to cause it to oscillate about anaxis normal to the axis of reciprocation of the piston means through anarc of more than 180° C.
 3. An apparatus as claimed in claim 1, in whichthe piston members are joined together externally of the tube in amanner such that the distance between the opposed faces of the axiallyaligned pistons may be varied to enable the length of the discreteproduct units to be correspondingly varied.
 4. An apparatus as claimedin claim 1 in which a lubricant is applied to the ends of the pistonmembers in contact with the product units.
 5. An apparatus as claimed inclaim 1 in which the paste-like material is supplied to the inlet portby a line connected to the inlet port and a pressurized sourcecontaining the said material.
 6. An apparatus as claimed in claim 1, inwhich the tube has an air bleed hole intermediate the inlet port and theopen end of the tube.